O RLY is internet slang for “OH REALLY?” with implicit sarcasm. Since gaining traction through with usage on Internet forums, O RLY has become a popular deadpan response to any statement that is deemed either highly doubtful or obviously true.

“All Your Base Are Belong to Us” is a classic catchphrase that has been spawning derivatives at some level since at least 1998. Most of the early derivatives took the form of image macros and Flash animations, although the meme has spread to YouTube videos as well.